| Description | Inquire | The bacterial viability / toxicity detection kit contains two fluorescent dyes. Nucgreen is a green nucleic acid dye that can stain live and dead bacteria; Ethd III is a red nucleic acid dye that only stains dead bacteria with damaged cell membranes. When nucgreen and ethd III are properly mixed, The bacterial viability / toxicity detection kit contains two fluorescent dyes. Nucgreen is a green nucleic acid dye that can stain live and dead bacteria; Ethd III is a red nucleic acid dye that only stains dead bacteria with damaged cell membranes. When nucgreen and ethd III are properly mixed, the bacteria with intact cell membrane appear green, while the bacteria with damaged cell membrane can appear green and red under different channels, respectively. A common criterion for bacterial viability is the ability to propagate in a suitable nutrient medium, known as a growth assay. This kit is generally in good agreement with the growth assay results in liquid or solid medium. However, under certain conditions, membrane damaged bacteria may recover and propagate in nutrient medium, and such bacteria will be identified as dead bacteria in this assay. On the contrary, some bacteria with intact membranes may not be able to propagate in nutrient medium, but will be recognized as viable bacteria in this assay. Therefore, if there is a large difference between the test results of this kit and the bacterial growth assay, the above possibilities should be considered. Component： Product parameters： NucGreen: Ex/Em = 503/530 nm (结合 DNA)；EthD-III: Ex/Em = 530/620 nm (结合 DNA)。Usage:1 Preparation of control samples for live and dead bacteria (optional)1. Cultivate 4 mL of bacteria in liquid medium until late logarithmic phase.2. Prepare two 1 mL bacterial solutions in an EP tube and centrifuge for 10-15 minutes under 5000-10000 g conditions.3. Remove the supernatant and add 0.3 mL of 0.85% NaCl resuspended bacteria to one of the EP tubes, and 1 mL of 0.85% NaCl resuspended bacteria to the other tube.4. Add 0.7 mL of isopropanol to a tube containing 0.3 mL of 0.85% NaCl, and mix thoroughly (with a final concentration of 70% isopropanol) to prepare a dead bacterial sample.5. Incubate the two samples at room temperature for 1 hour and mix every 15 minutes.6. Centrifuge the two samples at 5000-10000 g for 10-15 minutes.7. Remove the supernatant, add 1 mL of 0.85% NaCl to resuspend the bacteria in both samples, and centrifuge again as in step 6.8. Use a spectrophotometer to measure the absorbance values (OD670) of two bacterial suspensions at 670 nm.9. Adjust the density of the two bacterial suspensions (live and dead) to 108 bacteria/mL (OD670 ≈ 0.3), and then dilute with 0.85% NaCl at 1:100 to achieve a final density of 106 bacteria/mL.10. Mix two bacterial suspensions as shown in the table below to obtain the required live cell ratio: dead cell ratio.Table 1 Mix live and dead bacterial suspensions by a certain volume to achieve the required ratio of live and dead cellsLive cells: Dead cellsVolume of viable bacterial suspension（mL）Volume of dead bacterial suspension（mL）0:10001.010:900.10.920:800.20.830:700.30.750:500.50.5100:01.00II Staining methods for fluorescence microscopy observation1. Mix 1 volume of component A, NucGreen, and 2 volumes of component B, EthD-III, in a microcentrifuge tube. After thorough mixing, add 8 volumes of 0.85% NaCl solution to obtain a 100 x dye solution.2. Every 100 µ L bacterial suspension, add 1 µ 100 x dye solution of L.3. Mix thoroughly and incubate at room temperature in the dark for 15 minutes.4. Take 5 µ The bacterial suspension after L staining was dropped onto a glass slide with an 18 mm square cover glass.5. Observe under a fluorescence microscope. The fluorescence of live and dead bacteria can be observed simultaneously under any standard FITC long-acting filter. Alternatively, live (green fluorescent) and dead (red fluorescent) bacteria can be observed using FITC and Cy3 (or Texas Red) channels, respectively.Attention: (1) Before staining bacteria, attention must be paid to removing residues of growth media. Nucleic acid and other media components can bind to NucGreen and EthD-III dyes in some way, resulting in unacceptable staining changes. A simple washing step is usually sufficient to remove interfering media components from bacterial suspension. It is not recommended to use phosphate buffer solutions as they can reduce staining efficiency. (2) Before starting the formal experiment, the dye concentration should be adjusted to distinguish between NucGreen labeling live bacteria and EthD-III labeling dead bacteria. The optimal concentration may vary depending on the bacterial strain. It is generally best to use the lowest dye concentration that can provide sufficient signal. The above conditions have been optimized for staining live/dead cells of Escherichia coli.III Before starting the staining method experiment of flow cytometry, please read the precautions under the fluorescence microscope staining steps.According to Table 1, add 11 different proportions of live and dead bacteria to the EP tube. Each of the 11 samples has a volume of 1 mL.2. Add 12 µ The A component of L, NucGreen, and 24 µ The B component EthD-III of L was mixed in a microcentrifuge tube. Add 3 to each of the 11 samples µ Mix the mixed dyes of L thoroughly by blowing them up and down several times. (Note: Additional control bacterial samples need to be prepared for separate NucGreen and EthD-III staining)3. Incubate at room temperature in the dark for 15 minutes.4. Analyze each sample using a flow cytometer, detect NucGreen positive cells using FITC channels, and detect EthD-III positive cells using PI or PE channels.Matters needing attention：1. please centrifuge the product to the bottom of the tube immediately before use, and then conduct subsequent experiments. 2. if the orifice plate is used for detection, a small amount of bacterial liquid can be left for imaging after standing for 10 min, which can effectively reduce the background. 3. in order to be closer to the real results, it is recommended to keep the brightness of red fluorescence consistent with that of green fluorescence in merge pictures. 4. fluorescent dyes have quenching problems. Please try to avoid light during experimental operation to slow down fluorescence quenching. 5. for your safety and health, please wear experimental clothes and disposable gloves.Scope of application：Staining of dead and live bacteria... Read More | Format:2-ComponentEnzyme:Horseradish peroxidase | EndoFree Plasmid Midi Kit Cat No. Component Size（50T） Storage E665631A Buffer P1 30 mL RT E665631B Buffer P2 30 mL RT E665631C Buffer E3 30 mL RT E665631D Buffer PS 15 mL RT E665631E Buffer PW (concentrate) 10 mL RT E665631F Endo-free Buffer EB 10 mL RTEndoFree Plasmid Midi Kit Cat No. Component Size（50T） Storage E665631A Buffer P1 30 mL RT E665631B Buffer P2 30 mL RT E665631C Buffer E3 30 mL RT E665631D Buffer PS 15 mL RT E665631E Buffer PW (concentrate) 10 mL RT E665631F Endo-free Buffer EB 10 mL RT E665631G RNase A (10 mg/mL) 600 µL RT E665631H Buffer ER 8 mL RT E665631I CWBlue 300 µL RT E665631J Spin Columns DL with Collection Tubes 50 EA RT E665631K Endo-Remover FM with Collection 50 EA RTProduct Introduction:Endotoxins are a common pollutant in plasmid extraction. Due to the high sensitivity of eukaryotic cells to endotoxins, the presence of endotoxins in plasmids can greatly reduce the transfection efficiency of eukaryotic cells. This reagent kit provides a simple, fast, and efficient new method for extracting endotoxin free plasmids. The extracted plasmids can remove endotoxins to the maximum extent possible and effectively remove contamination of genomic DNA, RNA, proteins, and other substances. This reagent kit is suitable for extracting 5-15mL of bacterial solution. On the basis of alkaline lysis of cells, it efficiently and specifically binds plasmid DNA through a new silicon-based membrane. Each adsorption column can adsorb up to 100 µ The plasmid DNA of g is effectively removed using a special buffer system and endotoxin removal filter column, effectively removing impurities such as endotoxins and proteins. The plasmid obtained from this kit has high purity and stable quality, making it particularly suitable for cell transfection. It can also be used for downstream experiments such as DNA sequencing, PCR, PCR based mutations, in vitro transcription, transformed bacteria, and endonuclease digestion.Self prepared reagents: anhydrous ethanol, isopropanol.Preparation and important precautions before the experiment:1. All components can be stably stored in a dry, room temperature (15-30 ℃) environment for 1 year, and can be stored at 2-8 ℃ for longer periods of time. Buffer P1 with RNase A added can be stably stored at 2-8 ℃ for 6 months.2. Before the first use, add all RNase A solution to Buffer P1, mix well, and store at 2-8 ℃. Before use, let it sit at room temperature for a period of time. After returning to room temperature, use.3.Before the first use, anhydrous ethanol should be added to the Buffer PW according to the instructions on the reagent bottle label.4. Before use, please check if there is any crystallization or precipitation in Buffer P2 and Buffer E3. If there is any crystallization or precipitation, you can take a water bath at 37 ℃ for a few minutes to restore clarity.5. Be careful not to come into direct contact with Buffer P2 and Buffer E3, and immediately cover them tightly after use.6.The amount and purity of plasmid extraction are related to factors such as bacterial culture concentration, strain type, plasmid size, and plasmid copy number.Operation steps:1. Take 5-15 mL of overnight cultured bacterial solution and add it to a centrifuge tube (self provided). Centrifuge at 13000 rpm (~16200 × g) for 1 minute to collect bacteria, and try to discard all the supernatant as much as possible.2. Add 500 to the centrifuge tube containing bacterial sediment µ L Buffer P1 (please check if RNase A has been added first), mix thoroughly with a pipette or vortex oscillator, and suspend bacterial precipitation. Attention: If the bacterial blocks are not thoroughly mixed, it will affect the cracking effect, resulting in low extraction amount and purity.3. Add 500 to the centrifuge tube µ L Buffer P2, gently invert and mix 8-10 times, allowing the bacterial cells to fully lyse. Leave at room temperature for 3-5 minutes. At this point, the solution should become clear and viscous. Attention: Mix gently and do not shake vigorously to avoid interrupting genomic DNA and mixing genomic DNA fragments in the extracted plasmid. If the solution does not become clear, it indicates that the bacterial count may be too high and the lysis may not be complete. The bacterial count should be reduced.4. Add 500 to the centrifuge tube µ L Buffer E3, immediately invert and mix 8-10 times until white flocculent precipitates appear. Let it stand at room temperature for 5 minutes. Centrifuge at 13000 rpm for 5 minutes, extract the supernatant, and add it to the filter column (Endo Remove FM) (already loaded into the collection tube). Centrifuge at 13000 rpm for 1 minute to filter, then transfer the filtrate from the collection tube to the centrifuge tube (self provided). Attention: 1) After adding Buffer E3, it should be immediately mixed to avoid local precipitation. 2) The maximum volume of the adsorption column is 750 µ L. So please filter the supernatant twice and mix it in the same self provided centrifuge tube.5. Add 450 to the filtrate µ Mix L isopropanol upside down.6. Column balance: Add 200 to the spin columns DL that have been loaded into the collection tube µ L Buffer PS, centrifuge at 13000 rpm for 2 minutes, discard the waste liquid in the collection tube, and place the adsorption column back into the collection tube.7. Transfer the mixed solution of filtrate and isopropanol from step 5 to an equilibrium adsorption column (already loaded into a collection tube). 8.13000 rpm for 1 minute, discard the waste liquid in the collection tube, and place the adsorption column back into the collection tube. Attention: The maximum volume of the adsorption column is 750 µ L. So the solution obtained in step 5 is divided multiple times and passed through the column. 9. Add 750 to the adsorption column µ L Buffer PW (please check if anhydrous ethanol has been added first), centrifuge at 13000 rpm for 1 minute, and discard the waste liquid in the collection tube.10. Place the adsorption column back into the recovery manifold and centrifuge at 13000 rpm for 1 minute.Note: The purpose of this step is to remove residual ethanol from the adsorption column, which can affect subsequent enzymatic reactions (such as enzyme digestion, PCR, etc.).11. Place the adsorption column in a new centrifuge tube (self provided)... Read More | R669988 Component 50T Storage R669988A DNase I 1000 U -20℃. Avoid freeze/thaw cycle. R669988B 10×Reaction Buffer 1000 µL -20℃. Avoid freeze/thaw cycle. R669988C Buffer RL 35 mL RT R669988D Buffer RLC 35 mL RT R669988E Buffer RW1 40 mL RT R669988F Buffer RW2 (concentrate) 11 mL R669988 Component 50T Storage R669988A DNase I 1000 U -20℃. Avoid freeze/thaw cycle. R669988B 10×Reaction Buffer 1000 µL -20℃. Avoid freeze/thaw cycle. R669988C Buffer RL 35 mL RT R669988D Buffer RLC 35 mL RT R669988E Buffer RW1 40 mL RT R669988F Buffer RW2 (concentrate) 11 mL RT R669988G RNase-Free Water 10 mL RT R669988H Spin Columns FL with Collection Tubes 50 sets RT R669988I Spin Columns RM with Collection Tubes 50 sets RT R669988J RNase-Free Centrifuge Tubes (1.5 mL) 50 EA RTProductsThis kit is used for the extraction and purification of high-quality total RNA from a variety of plants, and is also suitable for the extraction of fungal mycelial RNA. The unique separation column is used for homogenization and filtration of high viscosity plant or fungal lysates, while the silicon matrix membrane is used to adsorb the RNA for purification, so that various contaminants, such as polysaccharides, are effectively removed by washing, and the eluted RNA can be directly used in various downstream experiments. The molecular weight of RNA extracted by this kit is more than 200 bases, with high purity and almost no DNA residue. For RNA experiments that are very sensitive to trace DNA, the residual DNA can be removed by digestion on a column using RNase-free DNase. The extracted RNA can be used in Northern Blot, Dot Blot, RT-PCR and in vitro translation experiments.Self-contained reagents: β-mercaptoethanol, anhydrous ethanol (freshly opened or for RNA extraction).Pre-experiment Preparation and Important Notes1. To prevent RNase contamination, attention should be paid to the following aspects:1) Use RNase-free plastics and tips to avoid cross-contamination.2) RNase-free water should be used to prepare the solution.(3) Operators wear disposable masks and gloves, and change gloves diligently during the experiment.2. To prevent RNase contamination, attention should be paid to the following aspects:1) Use RNase-free plastics and tips to avoid cross-contamination.(2) Glassware should be dry-roasted at 180°C for 4 hours before use, and plasticware can be soaked in 0.5M NaOH for 10 minutes, rinsed thoroughly with water and autoclaved.3) RNase-free water should be used to prepare the solution.(4) Operators wear disposable masks and gloves, and change gloves diligently during the experiment.3. Avoid repeated freezing and thawing of the extracted samples, otherwise it will affect the amount and quality of RNA extraction.4. Please add β-mercaptoethanol to Buffer RL before use, add 10µl of β-mercaptoethanol to 1ml of Buffer RL, it can be stored for 1 month at room temperature. Buffer RL with β-mercaptoethanol can be stored at room temperature for 1 month. β-mercaptoethanol is not required for use of Buffer RLC.5. Anhydrous ethanol should be added to Buffer RW2 before first use according to the instructions on the reagent bottle label.6. If precipitation occurs in Buffer RL and Buffer RLC, heat to dissolve and leave at room temperature.7. All centrifugation steps are carried out at room temperature and all steps are performed quickly. Procedure1. 50-100 mg of plant tissue is quickly ground to a powder in liquid nitrogen and added to 600 µl of Buffer RL (check for addition of β-mercaptoethanol before use) or Buffer RLC. vortexing and oscillating to allow for adequate lysis.Note: 1) The main component of Buffer RL is guanidine isothiocyanate, which is suitable for lysis of most plant tissues. However, in some plant tissues (e.g. endosperm of corn), due to the special secondary metabolites, guanidine isothiocyanate causes precipitation of the sample, resulting in poor RNA extraction, in this case, Buffer RLC can be added instead of Buffer RL.2) Incubation at 56°C for 1-3 minutes helps tissue lysis, but do not incubate at high temperatures for plants with high starch content.2. Transfer all the liquid obtained in step 1 to an adsorption column (Spin Columns FL) that has been loaded into a collection tube, centrifuge at 12,000 rpm (~13,400 x g) for 2 minutes, and transfer the supernatant from the collection tube to a new centrifuge tube (supplied).Note: 1) The tip of the tip of the gun can be cut off when aspirating liquids to facilitate sampling.2) Spin Columns FL removes most of the debris, but a small portion will still flow out and a precipitate will form in the collection tube after centrifugation, so be careful to avoid aspirating the precipitate when proceeding to the next step.3. Add 0.5 times the volume of anhydrous ethanol to the clean lysate obtained in step 2 and mix rapidly.Note: Precipitation may occur upon addition of ethanol, but does not affect subsequent tests.4. Transfer the solution obtained in the previous step to the Spin Columns RM in the collection tube. If it is not possible to add all of the solution to the column at one time, centrifuge the column at 12,000 rpm for 15 seconds in two batches, discard the waste solution and put the column back into the collection tube.5. Add 350 µl Buffer RW1 to the adsorbent column, centrifuge at 12,000 rpm for 1 min, discard the waste liquid and put the adsorbent column back into the collection tube.6. Preparation of DNase I mixture: Take 52µl of RNase-Free Water, add 8µl of 10×Reaction Buffer and 20µl of DNase I (1U/µl) to it, mix well, and make a final volume of 80µl of reaction solution.7. Add 80µl of DNase I mixture directly to the adsorption column and incubate at 20-30°C for 15 minutes.8. Add 350 µl of Buffer RW1 to the adsorption column, centrifuge at 12,000 rpm for 1 minute, discard the waste liquid and put the column back into the collection tube.9. Add 500 µl of Buffer RW2 to the column (check that anhydrous ethanol is added before use), centrifuge at 12,000 rpm for 15 seconds, and discard the waste solution.10. Repeat step 9.11. Place the adsorbent column back into the collection tube, centrifuge at 12,000 rpm for 1 minute, and allow the column to come to room temperature for a few minutes to thoroughly dry out the anhydrous ethanol in the adsorbent column.Note: The purpose of this step is to remove residual ethanol from the adsorption column; ethanol residue can interfere with subsequent enzymatic reactions (zymography, PCR, etc.).12. Load the adsorption column into a new centrifuge tube, add 30-50 µl of RNase-Free Water to the middle of the adsorbent membrane, leave it at room temperature for 1 minute, centrifuge at 12,000 rpm for 1 minute, and store the resulting RNA solution at -70°C to prevent degradation.Note: 1) The volume of RNase-Free Water should not be less than 30 µl, too small volume affects the recovery rate.2) If you want to increase the RNA yield, repeat step 12 with 30-50 µl of fresh RNase-Free Water.3) If the RNA concentration is to be increased, the resulting solution can be reintroduced into the adsorption column and step 12 repeated... Read More |